Abstract: Great thermal bending of aeroengine, especially high pressure (HP) rotor, is come into being frequently in course of cooling after parking. When the rotor system starts up again, it brings relative big thermal vibrations which threaten the safe operation of aeroengine. In this paper, the thermal vibration characteristics of HP rotor system of certain aeroengine were studied by means of the coupling theory of flow-thermal-structure-dynamics. The effect of temperature in different parking times on dynamics characteristics for HP rotor was discussed. At same time the calculated results were compared with experiment. The results show that during 65~90min, the maximal vibration velocity of HP rotor exceed critical safe vibration velocity, 80mm/s. So when the rotor starts up after parking, it should be avoid the times of 65~90min to minish thermal vibration velocity. Or after cooling running, the rotor start up again. The calculated results offer theoretical direction of design and fault diagnosis of HP for avoiding thermal vibration.